... Contact Tach Photoelectric Tachometer Digital Laser Photo Tachometer DT6234B RPM Non Contact TachPhotoelectric TachometerDetailed Product DescriptionTachometer 1)contact tach ... range: 2.5~99,999 RPM 2)resolution: 0.1 rpm / 1 rpm 3)MAX,MIN,last value memory, can ... AA Size Battery or to externalDC 6V Regulated power supply Package Include:1x digital tachometer 1x carring case 1x English ...